Need an API that allows me to load a shared object from a memory address

Question

The dlopen prototype: void *dlopen(const char *filename, int flag);

What I need is: void *dlopen(const char *pBufferWithSoContents, int flag);

I don't want to store the library.so in a filesystem. I want to store it in a memory buffer, not in a files system. Anyone know of any solutions I could use?

Do you have a filesystem? Have you tried to write your data to a temporary file and than use dlopen? — Jonatan Goebel, Apr 14 '15 at 21:12
I have a file system but I don't want to use it. This is a specialized use case. — MatchPoint, Apr 14 '15 at 21:13
You might as well static link it which is what you are basically describing? Tell me why you can't just static link which means the code becomes part of the executable. — Daniel Lopez, Apr 14 '15 at 21:20
depending on your use case, the most pragmatic solution might be to just dump a file into `/tmp`, which may or may not be backed by on-disk storage — Christoph, Apr 14 '15 at 21:25
Tmp file is the solution check my answer see if it helps I haven't tested the code. — Daniel Lopez, Apr 14 '15 at 21:27
see also the related question [dlopen from memory?](http://stackoverflow.com/questions/5053664/dlopen-from-memory?rq=1) — Christoph, Apr 14 '15 at 21:28
Yes this is a possible duplicate. But I might be wrong. Just flagged it for review. — Daniel Lopez, Apr 14 '15 at 21:35
Could you give us more information about your real problem? Explaining why you cannot create a temporary file or static link your object? — Jonatan Goebel, Apr 14 '15 at 21:47
@Christoph - thanks, that guy wants the same thing which renders my a post a re-post. Unfotunately, there isn't any way to this. — MatchPoint, Apr 14 '15 at 23:47
See also https://sourceware.org/bugzilla/show_bug.cgi?id=11767 — Employed Russian, Apr 22 '15 at 04:26

score 0 · Answer 1 · answered Apr 14 '15 at 21:27

0

void *dlopen(const char *pBufferWithSoContents, int size, int flag) {

FILE* handle = fopen("lib.tmp", "w");

fwrite(pBufferWithSoContents, sizeof(char), size, handle);

fclose(handle);

void * ptr = dlopen("lib.tmp", flag);

remove("lib.tmp"); // Tmp file delete it.

return ptr;

}

I must admit not tested but essentially create a tmp file. You said its in memory but not in hard disk just temporarily save it on the disk load it using the dlopen posix call and just delete the temporary file.

answered Apr 14 '15 at 21:27

Daniel Lopez

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You are still writing the lib to the file system by storing it lib.tmp, albeit briefly. – MatchPoint Apr 14 '15 at 23:53
That is the point there is no way you can load it in memory. If you can answer my question why can't you just temporarily store it on the disk? Is there some performance gain, I would not think not. – Daniel Lopez Apr 15 '15 at 00:41

Need an API that allows me to load a shared object from a memory address

1 Answers1